spi: atmel: remove useless include

Definitions from linux/platform_data/atmel.h are not used, remove the
include.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-atmel.c

@@ -19,7 +19,6 @@
 #include <linux/interrupt.h>
 #include <linux/spi/spi.h>
 #include <linux/slab.h>
-#include <linux/platform_data/atmel.h>
 #include <linux/platform_data/dma-atmel.h>
 #include <linux/of.h>